Prep the salmon: Pat the salmon dry with paper towels and season lightly with salt and pepper. This helps the crust adhere and ensures a crisp surface.

Make the crust mixture: In a small bowl, combine the crushed nori, panko, sesame seeds, scallions (if using), and a pinch of salt. Stir in the mayonnaise or Dijon along with the soy sauce until the mixture forms a loose, scoopable paste.

Coat the salmon: Brush the top and sides of each fillet with a thin layer of the binder. Press the crust mixture onto the top, gently patting it so it sticks evenly and slightly wraps around the sides for extra crunch.

Sear: Heat 1 tablespoon of oil in a skillet over medium-high heat. Once shimmering, place the salmon crust-side down and sear for 2–3 minutes, until the crust turns golden and crisp. Flip carefully and sear the other side for 1–2 minutes, just to seal and warm through.

Optional finish: Transfer the skillet to a preheated 400°F (200°C) oven for 4–6 minutes if the fillets are thick or you prefer a fully cooked center. The crust should stay crisp and the fish should be opaque and flake easily with a fork.

Serve: Remove from heat, squeeze fresh lemon juice over the top, and let rest for a minute before serving. Enjoy the contrast of the hot, crunchy crust and tender salmon inside.